The direct-current characteristics and surface repairing of a hydrogen-terminated free-standing polycrystalline diamond in aqueous solutions

Abstract

As we know that more effective sy nthesis of diamond combined with physical and chemical properties of hydrogen termination in aqueous environment as well as device structure design can greatly facilitate the chemical and electrochemical applications of higher cost-performance diamond. For this purpose, the direct-current(DC)characteristics, surface reactionand reparation of a hydrogen-terminated DC arc jet plasma CVD polycrystalline diamond, which hasa high cost-performance, were characterized by I-V experimentsbased on aFET-like structure device in multipleaqueoussolutions.The variation trends of the I-Vproperties of device based on pH were similar indifferent aqueous solutionsbut could be affected by disparate ions (such as K + ions)or organic molecules(such as citric acid radicalsora benzene ring).Especially, owing to the founded replacement of hydrogen termination with hydroxyl (-OH),carboxyl radical (-COOH)or carbon-oxygen bond (-C-O-C-) in mixed solution, i.e.,KHP+ H 2 SO 4 (and +NaOH) solutions, the resistance of the device was remarkably increased from 13.57kΩto 95.78kΩ.However, the raised resistance of surface reacted diamond (SRD) can be reducedprominentlyby repairing hydrogenterminationthroughnegative potential sweeps (NPS)at a low negative potential (-1 to -3 V) ifthe SRDwas introduced as an electrode in a strong inorganic acid.What's more, the NPS repaireddevice, whichsubsequently stored for four weeks, wasmore sensitive than the original hydrogen plasma-treated diamond in aqueoussolution environments. This repaired resultwascoming out of NPS re-formed C-H bonds with higher intensity. These findings will be the references of failure and reparationof diamond hydrogen termination inaqueous environment.

Subsurface cleavage of diamond after high-speed three-dimensional dynamic friction polishing

“…For the 1425 cm -1 peak, it should have a high proportion of sp 3 bonding. In a tight binding molecular-dynamics (TBMD) simulation, some structure was observed between 1400 cm -1 and 1600 cm -1 which was attributed to localized bonding between threefold (sp 2 ) and fourfold (sp 3 ) coordinated carbon atoms. The frequency modes from 1300 cm -1 to 1500 cm -1 of fourfold atoms in the a-C network were found to be relatively localized with 20% to 30% of vibrational amplitudes on a pair of atoms.…”

“…The unique mechanical, electrical and optical properties of diamond make it an ideal material for a variety of advanced applications that could revolutionize current technology. Practically, diamond is available as single crystal (SCD), polycrystalline (PCD) and large wafers produced by chemical vapor deposition (CVD), which have numerous applications including optics, thermology, electronics and biology [1][2][3][4][5]. In order to fabricate high performance diamond-based devices, ultra-smooth surface (roughness average less than 5 nm or even less than 1 nm) and structurally damage-free diamond substrates are necessary for making ideal metallic contacts and device integration.…”

Demonstration of Monolithic Polycrystalline Diamond-GaN Complementary FET Technology for High-Temperature Applications

“…In this work, we focused on the monolithic integration method to fabricate a polycrystalline (PC) diamond hole FET and AlGaN/GaN HEMT simultaneously on a single chip to deliver a complementary inverter for high-temperature. Previous work showing that PC diamond hole FET using a PC diamond plate (Element six TM200) with an average grain size between 80 and 100 μm demonstrates comparable performance to the SC diamond hole FET in recent works, − pointing to the validity of our approach. In a separate study, the role of PC diamond as a heat spreader was also discussed, making this combination even more desirable for various applications .…”

Fast smoothing on diamond surface by inductively coupled plasma reactive ion etching

“…However, further increasing the CHF3 additive ratio to 20 %, the etching rate decreased. This is because more C ions were added simultaneously which facilitated the formation of CHx and HF (Equation 8); the excessive C atoms weakened the oxidation reaction owing to the reduced reaction of CO or C, which affected the surface bombardment, as shown by equation (2) and (8) [6]. The presence of H ions caused the diamond etching rate to increase faster than that with most other assisted gas additions in O2.…”

“…Owing to its outstanding mechanical, electrical, chemical, and thermal properties, diamond is far superior to many other materials and is a very attractive functional material for special tools, optical devices, biosensors, quantum computation, potential microelectronics and microelectromechanical systems (MEMS), as well as the next-generation wide band-gap semiconductor electronic devices [1][2][3][4]. One of its most notable properties is stability, which enables diamond to remain stable even in harsh environments such as abrasion, radiation, chemical corrosion, high temperatures, and high voltage [2,5,6]. Such stability, however, makes the diamond extremely difficult to process using ordinary machining methods, which had hindered its wide range applications.…”